Armature pump

ABSTRACT

An oscillating armature pump comprises a reciprocable armature piston having a pumping passage defined therethrough with a valve seat. The pump includes a housing having an inlet with an inlet valve seat which is closed by a suction valve member having a stem which extends through the piston opening and holds a piston valve off the seat of the piston opening in the inoperative position of the pump piston. The pump piston advantageously includes an extension through which it transmits a closing force to the suction valve in the inoperative position of the piston as a result of the biasing action of the main pump spring. The valve stem extension of the suction valve itself, also acts on the piston valve to maintain it off its seat by a small gap in the inoperative position. The piston valve is advantageously acted upon by the combined force of a pump spring and a pressure valve spring which is confined within a cage which is under biasing contact by the pump spring. The piston has a sleeve portion which is adapted to engage with the outlet member of the housing to limit the pump stroke.

United States Patent 2,488,384 11/1949 Dickeyetal 3,479,959 11/1969 Christensen ABSTRACT: An oscillating armature pump comprises a reciprocable armature piston having a pumping passage defined therethrough with a valve seat. The pump includes a housing having an inlet with an inlet valve seat which is closed by a suction valve member having a stem which extends through the piston opening and holds a piston valve ofi the seat of the piston opening in the inoperative position of the pump piston. The pump piston advantageously includes an extension through which it transmits a closing force to the suction valve in the inoperative position of the piston as a result of the biasing action of the main pump spring. The valve stem extension of the suction valve itself, also acts on the piston valve to maintain it off its seat by a small gap in the inoperative position. The piston valve is advantageously acted upon by the combined force of a pump spring and a pressure valve spring which is confined within a cage which is under biasing contact by the pump spring The piston has a sleeve portion which is adapted to engage with the outlet member of the housing to limit the pump stroke.

PATENTEnJuLlslsn 3,592,565

Siegfried Kofink %%r X M ATTORNEYS.

ARMATURE PUMP SUMMARY OF THE INVENTION This invention relates in general to the construction of pumps and, in particular, to a new and useful oscillating armature pump preferably for the delivery of liquid fuels, such as gasoline and which comprises an armature piston having an opening therethrough, which is closed by a piston valve; and wherein the pump inlet includes a valve having a stern portion which maintains the piston valve off its seat when the pump is in inoperative position.

The present invention deals particularly with pumps which are useable for example, for pumping fuel to a room heater. Because of the purpose of such pumps, they must be designed for high-safety operational requirements. Thus, for example, particularly in the inoperative position of the pump, the fuel inflow must be prevented by positive means. Oscillating type armature pumps are known but with such pumps having partly variable strokes the fuel is drawn through the suction valve and given ofi through a pressure valve. The known designs have the disadvantage that they leak at potential pressures and then small amounts of fuel are always admitted to the combustion chamber at the prevailing pressure. This is dangerous particularly in respect to a retarded ignition. Another disadvantage is that no air can be pumped with the known design of pumps.

In accordance with the present invention, there is provided an oscillating armature pump having a suction and a pressure valve and wherein the pressure valve is arranged within a pump piston having a flow passage defined therethrough which is closed by the valve. At the start of the delivery, the pump may be operated to draw in air and where the pressure valve is under an initial biasing tension the potential gradient on the pump has no influence on the quantity delivered. The pump of the invention includes a suction valve arranged to close the pump inlet. It includes a stern portion which extends through the opening of the piston to maintain the piston pressure valve off its seat and open in the inoperative position. A valve mechanism also includes a piston pressure spring which thus acts through the piston valve and through the valve stem to the inlet valve. Thus during the inoperative position of the pump piston the latter will press on the inlet valve so that the inlet valve will close off the inlet to the fuel. Thus any leakage at potential pressure is eliminated. In addition by prolonging the stem of the suction valve to engage the pressure valve of the pump piston and to lift the latter, a small gap will always be formed in the piston passage. By this measure air can be delivered during the oscillation of the armature piston and the suction valve can be so strongly pretensioned that the potential gradient on the pump will have no influence on the quantity delivered. In addition, the pump spring of the pump piston as well as the closing spring for the pressure valve of the piston will establish a force-transmitting connection through the valve and the stem of the suctionvalve to the suction valve. The stroke of the oscillating armature piston is limited by the construction of the cylinder and preferably by an outlet fitting which is adapted to contact the piston wall at the stroke limit point. With this arrangement'the quantity delivered can be variably set in a simple manner.

Accordingly, it is an object of the invention to provide an improved oscillatable valve construction having spring means for the piston valve which acts also on an inlet valve to insure that the inlet valve is closed in the inoperative position.

A further object of the invention is to provide a valve construction which includes an inlet valve having a stem portion which extends through a passage defined in the piston, the piston having a valve which is lifted by the stem in the inoperative position.

A further object of the invention is to provide an oscillatable armature pump which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention. A

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an axial sectional view of a solenoid pump constructed in accordance with the invention; and

FIG. 2 is a view similar to FIG. ll of another embodiment of the invention. 7

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in particular the invention embodied therein as indicated in FIG. ll, comprises a reciprocable armature pump which comprises a housing formed by an inlet fitting 1 and an outlet fitting 2 which are threaded into a central housing portion 3. A solenoid 4 is arranged around the central housing portion 3 and provides means for actuating and displacing an armature piston 6 which is in the form of a cylindrical member having a flow passage therethrough. The piston 6 reciprocates within the space defined between the end fittings 1 and 2 and within a metallic bushing 5, held therebetween. In the embodiment of FIG. I, the piston 6 has an extension 7 which may engage in a form-transmitting manner with a valve disc or inlet valve member 13 arranged to close inlet seats 17 at the end of the inlet passage 1a.

Within this cylindrical portion of the piston 6 there is arranged a piston valve or pressure valve 8 having a stem portion 8a and a disc portion 8b. A pressure valve spring 9 is arranged within an associated cage 11 and it biases the disc 8b downwardly against a seat 16 formed at the inner end of the passage defined in the piston 6. A pump spring 12 is arranged between the outlet member 2 and the cage 9 and also provides a downward biasing force on the piston 6. The distance between the piston 6, in its lower dead center position, and the abutment 2a of the outlet member 2 determines the stroke h.

A suction valve i3 is arranged to close a seat 17 at the end of the inlet passage la and it is surrounded by a suction valve spring 14 which acts as a return spring. The spring 14 is biased on its outer or upper end by a cage 15.

By a light adjustment of the valve stem 18 it is possible to set the pressure valve 8b so that it is lifted off the seat 16 even when the suction valve 13 is closed so that the gap S is formed. The coil 4 is connected to a suitable electrical current source at terminals 30 and 32 to provide a timed energization to reciprocate the piston 6.

In the embodiment indicated in FIG. 2, there is provided a pump which is substantially the same as that indicated in FIG. 1 and includes parts which are similarly designated but with a prime added thereto. In this construction the pump piston 6 does not have an extension, but a stem 18 of the suction disc 13 does extend through the piston passage to lift the valve disc 8b off its seat in the inoperative position. In this embodiment there is a force transmission between the piston 6' and the valve disc 8b of the suction valve through a spring 14' which bears between the inlet valve 13' and the piston 6'.

What I claim is:

ll. A reciprocatable armature pump, comprising a pump housing having an inlet fitting with an inlet passage terminating inside said housing in an inlet valve seat, an inlet valve adapted to close said inlet valve seat, said housing having an outlet fitting with an outlet passage at the opposite end of said housing from said inlet fitting, an armature piston displaceable in said housing located between said inlet and outlet fittings and having a pump passage therethrough, electromagnetic coil means for displacing said piston, a piston valve adapted to close the pump passage, and spring means urging said piston toward said inlet valve and closing said inlet valve in the inoperative position, said inlet valve having stem means engageable with said piston valve to lift said piston valve off its associated seat closing to open said pump passage when said inlet valve is in an inoperative position.

2. A reciprocatable armature pump, according to claim 1, wherein said spring means includes a pump spring and a closing spring disposed between said inlet fitting and said piston valve and establishing a force-transmitting connection between said valve seat and said inlet valve stem means.

3. A reciprocatable armature pump, according to claim 1, wherein said inlet fitting includes an extension portion, said piston having a wall engageable with said extension portion at the end of the piston stroke and defining a stroke limit for said piston.

4. A reciprocatable armature pump, comprising a pump housing having an inlet fitting with an inlet passage terminating inside said housing in an inlet valve seat, an inlet valve adapted to close said inlet valve seat, said housing having an outlet fitting with an outlet passage at the opposite end of said housing from said inlet fitting, an armature piston displaceable in said housing located between said inlet and outlet fittings and having a pump passage therethrough, electromagnetic coil means for displacing said piston, a piston valve adapted to close the pump passage, and spring means urging said piston toward said inlet valve and closing said inlet valve in the inoperative position, said piston having a rigid extension which is in direct contact force-transmitting engagement with said inlet valve in an inoperative position and holds said inlet valve closed. 

1. A reciprocatable armature pump, comprising a pump housing having an inlet fitting with an inlet passage terminating inside said housing in an inlet valve seat, an inlet valve adapted to close said inlet valve seat, said housing having an outlet fitting with an outlet passage at the opposite end of said housing from said inlet fitting, an armature piston displaceable in said housing located between said inlet and outlet fittings and having a pump passage therethrough, electromagnetic coil means for displacing said piston, a piston valve adapted to close the pump passage, and spring means urging said piston toward said inlet valve and closing said inlet valve in the inoperative position, said inlet valve having stem means engageable with said piston valve to lift said piston valve off its associated seat closing to open said pump passage when said inlet valve is in an inoperative position.
 2. A reciprocatable armature pump, according to claim 1, wherein said spring means includes a pump spring and a closing spring disposed between said inlet fitting and said piston valve and establishing a force-transmitting connection between said valve seat and said inlet valve stem means.
 3. A reciprocatable armature pump, according to claim 1, wherein said inlet fitting includes an extension portion, said piston having a wall engageable with said extension portion at the end of the piston stroke and defining a stroke limit for said piston.
 4. A reciprocatable armature pump, comprising a pump housing having an inlet fitting with an inlet passage terminating inside said housing in an inlet valve seat, an inlet valve adapted to close said inlet valve seat, said housing having an outlet fitting with an outlet passage at the opposite end of said housing from said inlet fitting, an armature piston displaceable in said housing located between said inlet and outlet fittings and having a pump passage therethrough, electromagnetic coil means for displacing said piston, a piston valve adapted to close the pump passage, and spring means urging said piston toward said inlet valve and closing said inlet valve in the inoperative position, said piston having a rigid extension which is in direct contact force-transmitting engagement with said inlet valve in an inoperative position and holds said inlet valve closed. 